Genes & Cells

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NOT DEAD YET Cells on the brink of dying from a type of programmed suicide known as apoptosis (left, a cancer cell known as a HeLa cell) can come back to life through a process called anastasis (right) if conditions improve. DNA is shown in blue.

Ho Lam Tang

ENVIRONMENTAL EXPOSURES Things people come in contact with every day, such as pesticides, chemicals in water, hormone-mimicking chemicals in cash register receipts, smoke and air pollution, can change chemical tags on DNA and proteins. What those changes mean and how useful they are for determining health risks aren’t yet clear.

TINY BUBBLES Cooking up Earth’s first life probably required many “pots.” Spatial segregation into different pools or separate droplets might have helped the first self-replicating molecules survive. Later, protocells like those shown here provided more stable compartmentalization.